The proposed study is a continuation of a 3-year study that has demonstrated the feasibility of typing prostatic tissue, particularly cancerous tissue, through the use of spectrum analysis of ultrasonic echo signals. These studies have shown that spectrum-analysis methods can effectively differentiate cancerous from benign conditions, including prostatic hyperplasia, with sufficient sensitivity and specificity to produce an ROC curve area of 0.88. As in the 3-year study, the proposed studies will be undertaken collaboratively by scientists and engineers at Riverside Research Institute (RRI) and medical personnel at the Memorial Sloan-Kettering Cancer Center (MSKCC) in New York City. The proposed studies have 2 general purposes: 1) to expand the data base of spectrum- analysis parameters and histopathologically-determined prostatic-tissue types as obtained from biopsy, prostatectomy and male cystectomy, and 2) to evaluate the efficacy of parameter-value images for improving the planning and guidance of biopsy, surgery, cryotherapy, and radiation therapy and for monitoring therapies such as neoadjuvant (hormonal), conformal-radiation, and nutritional treatments. The proposed studies are planned to test specific hypotheses regarding the ability of spectrum analysis methods to differentiate among prostate-tissue types and to provide clinically-useful portrayals of tissue type that can enhance patient management, e.g., by reducing the number of true- and false- negative biopsies through better planning and guidance and by reducing the number of surgical treatments involving extracapsular cancer. Male patients of the Urologic Surgery Service and the Prostate Diagnostic Center of MSKCC will be scanned over the entire volume of the gland prior to prostate biopsy, prostatectomy, and cystectomy. Acquired ultrasonic signals will be analyzed and correlated with tissue assessments obtained histopathologically, and in the case of excised glands, in 3D. Patients who are not immediately treated surgically will be followed and the course of disease over time will be evaluated and biopsy results will be correlated with ultrasound-signal analyses. (Neoadjuvant treatment is administered prior to surgery and always ultimately provides histological information from excised glands for correlation with ultrasound-signal analyses.) RRI will be the prime grantee and MSKCC will participate through a subcontract with RRI.